Why Do We Love Rounded Corners?

As interface and graphic designers, we border on obsessed with rounded corners. Web developers have gone togreatlengths, through the creative use of CSS (and sometimes Javascript) to make the creation of rounded corners as painless as possible. The proposed CSS3 specification even includes properties for rounded corners (Firefox already supports it).
So why is there such a fascination with rounded corners? I would venture that our attraction to rounded corners goes beyond the aesthetic and speaks to something more.

On one level, I think we’re attracted to things that appear to be organic in nature. Take the iPod for instance. While the industrial design of similar products clearly hints towards how the device came to be, Apple put a lot of effort into creating a device that feels more like it grew on a tree than assembled in a factory. They went to great pains to conceal the machine-like characteristics that would typically hold a device together (screws, etc.). The result is a smoother feel with very few edges or hard angles to be found. This “smoothness” not only speaks to usability but also fosters an emotional connection with the device. Some of our earliest memories are tied to objects and things that are far less than perfect and rife with right angles. Corners say “go away.” At the risk of sounding hoaky: smoother, rounder surfaces say “hold me.”
Beyond physical objects, there is also appeal to presenting information and the controls around information in a more organic context than just boxes and right angles. When we’re introduced with a complex set of information, especially a set that is unfamiliar to us, one of the first things we do is survey the information and apply context wherever we can. “This bundle of information is associated with that title. This group of buttons over there is clearly associated with that piece of information.” Etc.As information architects and interaction designers, much of our work involves helping users make sense of the information and controls in front of them. In other words, we provide them with visual hints that guide them along the process of applying context to the interface in front of them. Rounded corners are a great way to do just that. Unlike plain old boxes with right angles, rounded corners clearly hint to what is inside ofand part of this cluster of information and what isn’t. When designers use solid colors it adds another level of reinforcement of context: the illusion of weight and volume.
Both explanations I’ve laid out above have one common denominator: they appear to leverage our own, very basic understanding of how we interact with and use objects in the physical world. The world is comprised of discrete objects that have their own integrity and are clearly separate from everything else (a beach ball, for example, is clearly its own thing not tied to anything else). Some objects even have controls on them that allow you to manipulate them. The knobs on your toaster, by virtue of being attached to your toaster, clearly control the toaster and not your refrigerator.
Rounded corners speak to and leverage this basic “expertise” we all possess and use to interact with the world around us. I’m pretty convinced that the appeal is beyond aesthetic. When used judiciously, we can create more intuitve experiences through such devices.
This article is based partly on a paper I wrote called Information Objects. For anyone who’s interested, It’s availabe in PDF format for download.Update: A related article has recently been posted that explores the use of open space in visual design.

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richz

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102 Comments →Why Do We Love Rounded Corners?

Another explanation is (could be) that rounded objects are likely or appear as being used more often. Like these are worn out paths or stones that are used a lot. (a walked, proven, comforting path). Gives a trustworthy feel to it.

HP (Hewlett Packard) made particularly good use of rounded corners for reasons similar to those you describe here. They seem to have ditched them now but that is probably because they have ditched the way they were heading. Nice entry.

The question really is: Are rounded corners ever going to go out of fashion?
For a long time now, I’ve noticed, at least in the UK that Rounded Corners have not been limited to the web or mp3 players, cars have become more rounded and bulbous.
I’m just scared that soon we will be living in a giant bubble world. Unless of course Apple decides to patent Pi.

Going along with Robin’s comment, I think a good point to make is that fashion plays a good part of the rounded matter. Trends tend to go in 20 or 30 year cycles of alternating roundness and squaredness.
But richz, I think you make a good point about the practicality of roundness. However, it seems to apply moreso to the presentation of information.
I think though we are at a new time in this trend cycle. While the technological world has always been more squared because of utility and cost-effectiveness, hi-tech things are so commonplace now that companies are thinking more about the presentation. This is clearly where Apple stands. It’s a good thing, in my opinion, to have something man-made that looks beautiful.
But is it possibly just a trend? Look at cars from the 1940’s and 50’s – they’re bubble-like. mid 60’s through mid 80’s – squared. 90’s – bubble. 2000’s – odd mix of both.

I would describe the ‘naughties’ (2000>) as being more rounded and less bubble like. I like to think that this trend will end up somewhere in the middle with very tight clean looking rounded corners with straight lines and industrial polished surfaces. That’s just me though, and style is all about preference of one’s own taste.

Hi,
nice article but … i dont get it: You say that “Unlike plain old boxes with right angles, rounded corners clearly hint to what is inside of” – but why should that be true? The function of grouping information is provided by both boxes equally …

Yes, an I-Pod with its rounded corners is very stylish as it is standalone. And also screen design can be so. But if only rounded corners are used nothing is accentuated, because everything is. And then, it gets very difficult to conceive the content immediately and clearly.

Square corners (in life) are all about efficiency – we pack things in cubes to make them fit better. So when we inject ‘style’ into an object, we tend to avoid that which implies the utilitarian. Even when we do adopt the square corners, we tend to add ornamentation and rondomness (eg. much of the work of architect FLR) to give the impression of something other than ‘squareness’. Square is believed to be dull and boring, therefore round must be chic and interesting.

Trivia: Apple lost that age-old court battle with Microsoft but one of the things they were left with was a patent on rounded-corner buttons. Which is why all buttons on Windows to this day are squared off. ;)

The Roman perfected the art of making things look visually perfect. For instance, a row of parallel columns sitting perpendicular to the ground looks cooked to the human eye so Roman architects would slightly tily the columns from the outside to the indise. A similar reasoning may be behind why rounded corders make square objects look more “perfect” to the human eye then perfectly square corners. Square cornered boxes tend to look bowed.

Some great feedback here.
I thought about mentioning how we associate pain with sharp objects, but I thought it would have been a bit of a stretch.
Does anyone with a background in architecture (as in real, physical architecture) have thoughts on this? Maybe from theories taught in school, etc?

things that represent fertility (boobs, butts, lips) are round (to sum up a few creative points from above :) )

So to say something looks “organic” and is therefore more “appealing”, it’s interesting that in our age of efficiency and technology, we still have the same desires we had millions of years ago. I guess we should just try to remember that we’re still human animals. (Apologies to Creationists, this is merely my humble opinion and I respectfully disagree with yours)

I think it has a lot to do with fashion. Between the end of the 70s and for most of the 80s sharp corners were definitely hip (think for instance about cars and builidings those years). And in general in art history there’s always been alternance between straight lines and curves. I won’t be surprised that in less than 10 years time sharp corners will be back…

Jan asks why rounded corners group information better. I believe it is because rounded corners make the grouping delimiters much more distinguishable by subtly adding a little bit of white space (the space that would otherwise be inside the square corner). Draw four rounded corner boxes, arranged tightly in a 2×2 manner, and then four square corner boxes similarly, and observe the difference.

90 degree angels are compositional terminators (e.g. they tend stop or start a composition with a fixation. A round corner causes limited fixation). Rouned corners are used to great effect so you don’t notice them and they dont interfere with the design. In industral design they are used to protect the user of the object since non-rounded corners are painfully sharp.

I am an architecture student who occasionally dallies with round corners. The industry however has a love-hate relationship with them.
At some point it represents the anti-thesis to the mechanical, yet to others it simply shows the unwillingness to accept the futile fight against more efficient factory-line production (cost). Round corners = less usable space.
Me? I think it’s mostly a trend and partly practical (wear/tear/scratches). But has anyone considered that it’s appeal also be largely a factor of the fact that everyone consciously or subconsciously knows that it’s harder and more expensive (in the case of objects) to make a curve?- it shouts: quality, attention to detail and thus better value and ‘design’.
As for interface designs- organic designs are always harder to do, to plan, to arrange without looking bad: can you imagine if all these grey comment boxes were rounded at the edges? It takes restraint to do it right. Yet precisely because of that- a ‘well-rounded’ design would speak volumes about quality, effort, and more importantly as mentioned, the desire to ‘humanise’ our surroundings.

I remember Nokia having this ad campaign about 5 years ago. “There are no sharp corners on the human body.” The text was accompanied by images of body parts. I think that the industry is kind of thinking the way you do.

Rounded corners are professional. Thats the main reason for their popularity. Something you built at home in your basement would be jagged and rough, an amatuer web designer would use only straight edges. Its for these reasons, things with rounded corners appear well built. If I ever spend a lot of time on a project I always try to “smooth out the edges”

Rounded corners are professional. Thats the main reason for their popularity. Something you built at home in your basement would be jagged and rough, an amatuer web designer would use only straight edges. Its for these reasons, things with rounded corners appear well built. If I ever spend a lot of time on a project I always try to “smooth out the edges”

Another idea I haven’t seen mentioned here, is the one of sexual attraction. It has been proven that men have a natural sexual attraction to rounded objects. This has long been thought to be an attraction to breast, and “child baring hips”. I don’t remember if it was the McKinsey study or another one, but they did find that even a plain red ball shown on a screen caused a momentary sexual response from males.

I have to agree with Kip partially. As a web developer, it is essentially harder to create rounded corners, so therefore it is desireable to show ability, etc. I don’t think the average user cares either way, its a designer/developer choice.

The reason CSS rounded corners are so hot is because standards-compliant designers were making square edged sites for 2 years straight and they were all looking the same and everyone knew it. What designer wants to look like everyone else.
Especailly when sites looked cooler with tables and images or in flash

Forget all the organic crap — Kip, Jim and Darryl are right: people like the rounded corners because it takes more work to make them. Therefore, if your product has rounded corners, it looks like you put more work into. On a website, it looks like you hired a professional to do it instead of throwing together some tables in Dreamweaver. And if you cared and had enough money to hire a good designer, you look more legitimate. For that reason, I disagree with Darryl because I think the average user can appreciate a design that says, “This takes skill,” even if they don’t realize it’s the rounded corners that project that image.

Square corners look cheap, that’s all. When I see a tab in a GUI, say, with a square corner, I think “the developer was too cheap to produce anything other than the sort of rectangle we’ve been seeing in GUIs for more than 20 years”.
On physical objects, rather than GUIs, hard corners are annoying. An ipod with a sharp corner in your pocket digs into your body. Walking into furniture with a sharp corner hurts. Lifting objects with sharp corners can sometimes be painful. And corners are more likely to result in damage to the item itself. Rounding off corners means that wear is spread more evenly over an item rather than being concentrated at the corners. And when that wear happens it’s less visible if the corner isn’t square.
No need for psychobabble to explain this.

There is actually a basis in human vision for rounded vs. squared corners. Studies that track eye movements have shown an attraction to features such as corners. Use of rounded corners will serve to exert less distracting pull on a viewer’s gaze.

i’m not sure that this is necessarily a psychological process, as much as it is a current trend is design. One could make the argument that one begats that other i suppose, but I don’t believe that’s the case.

We can come up with lots of clever reasons, but the honest answer is probably a lot simpler – it’s simply a trend. A style. Wait a couple of years and there will be another contemporary aesthetic that takes over.
If you want a more detailed explanation – rounded corners were difficult to do in the pre-digital days of design, especially print based design. So there is a novelty to having rounded corners. At some point rounded corners will be met with “god, that looks soooo early 2000s”.

Interesting article, I like rounded corners for a different reason though, and the same reason I like scalable vector graphics and round icons–round corners on web page boxes defy the standard that has been freely given to the designer, they are putting their own touch on it, customizing it, and making it more attractive and something different than the status quo. So I guess it is kind of the rebellion of rounded corners that attracts me in the design sense. Anyone can create a box, it takes some time and energy to create a rounded rectangle.

Another thought on this. The human eye tends to follow lines when examining something. If an object has sharp corners it would tend to throw the eye off the object, with a rounded corner it leads you round the corner to continue gazing at the object…
I think though that alot of the appeal of rounded corners is emotional rather than technical, so not so easy to quantify.

I agree that rounded corners (in terms of web design) make the end result look more “professional” in most instances, although that will change as it becomes easier for amateur designers to create more lush interfaces.
the real question is – if square is old, and rounded corners are what is “professional” now – what’s on the horizon? we’ve done the half & half – what’s next?

Interesting article but I agree with those who have mentioned that trends and fashion are the over-riding factors. We are naturally more impressed with things that are different to what is normal or default. In the computer world, square boxes are standard so rounded boxes look impressive. When rounded corners become so easy to make that they appear everywhere, then their appeal will diminish.
In web design, everyone, Amazon included, currently seems to love Apple-style translucent or reflective plastic-effect buttons. They’ll soon be old hat.
In hardware, the glossy white look of the iPod has been imitated to death. Now glossy black is the new white.
Come to think of it, rounded corners are only currently popular because Steve Jobs likes them.

‘AndyF’ touched on this earlier in the post and I wanted to add to that. The human eye (as described to me by my high school art teacher) is comprised of nerves that interpret horizontal movement (or lines), and vertical movement (lines). When you have an angle, or anything that involves more that a strictly vertical/horizontal plane, you are ‘exciting’ both sets of nerves at the same time. I think it’s for this reason that a curve (which involves a combination of h/v) draws our attention so much.
Also, I agree with the ‘organic’ and ‘well-built’ aspects mentioned earlier.
-TC

Good comments … though I think that if curves become too commonplace, there’ll be a counter-reaction against them in favor of hard, straight lines. Once or twice I’ve noticed in myself that when I move from an environment where everything is curved to one where it is straight and sharp-angled that the effect of the sharp angle feels bracing and solid. Ruthless, perhaps … but sometimes a bit of ruthlessness is can be nice.

Also, there’s a lot to be said for simplicity. When I first saw the Linux GUI, I was repulsed by its boxiness and seemingly clumsy icons. Since switching to Linux, I’ve become much more comfortable with them … they’re “simple” and “honest.”

“Apple put a lot of effort into creating a device that feels more like it grew on a tree than assembled in a factory.”
Sound thesis on the whole – but, whilst the iPod is a thing of natural simplicity, I’ve never seen any such thing growing on trees!

Circles vs squares, circles vs squares….. I think it’s a battle that will go on forever.
But then this is what I really think – in this never ending battle of squares and circles, the winners will be triangles!!! ;p

Hi Richz,
Love the article. Well done.
I think an earlier poster was right – you could use some some round corners here!
Feel free to contact us for a free copy of our EZRound software ( http://www.ezround.com ) and you folks can jazz the place up in minutes.
Team EZRound

Square corners look cheap, that’s all. When I see a tab in a GUI, say, with a square corner, I think “the developer was too cheap to produce anything other than the sort of rectangle we’ve been seeing in GUIs for more than 20 years”.
and
Rounded corners are professional. Thats the main reason for their popularity. Something you built at home in your basement would be jagged and rough, an amatuer web designer would use only straight edges. It
————————–
Excuse me while you all blow smoke up each others cracks but this is pure and total garbage.
How long does it take a ‘developer’ or a grade 7 student to do rounded corners?
Saying that this shows some kind of professionalism is like saying that you are a coder because you know some HTML.
Roundness is a cyclical thing which like fashion creeps up every once in awhile.
To try to seek the meaning of life from this is the very definition of navel gazing wankers with too much time and too much drugs.
darl

Square is the new round, geez guys get with it!!
I agree with Darl “Roundness is a cyclical thing which like fashion creeps up every once in a while”
It will come and it will go, How did I get to this site?

There’s another reason: rounded corners “point” to the center of the rectangle they surround. If you have lots of rectangles next to each other it’s often hard to tell from all the straight lines which of the two sides they belong to. Also, (as is visible in the comment boxes in this thread) the spaces between the rectangles are objects in their own right, which increases the complexity of the page. When looking at this page, is gray the background color, and the white bars are the objects, or is it the other way around?

With rounded rectangles the focus is on the interior of the rectangles and therefore they make stronger visual containers.

Absolute nonsense. I’ve seen plenty of designers rounding off everything in sight and ending up with a wishy-washy mess. When done properly, both can be equally stylish and effective as UI components. Rounded isn’t inherently better.
Anyway, my question to you all: Why Are RSS Feed Buttons Orange?

Much like the simple Penis, It is round so that one can lick and suck it and not get hurt. Since early childhood to our early teens we are slowly learning to lick and suck things that are rounded and soft looking. Hence the Penis has much to do with it.

I think ChrisW75 is correct. As a designer, I use rounded corners because a sharp corner can attract attention and provide an unwanted focal point. Rounded corners allow you to have a box without the distracting pointy bits.

Adi: it’s been there in Firefox for a very long time– possibly from before there was a Firefox, though my memory is a bit fuzzy– but you have to use the -moz- variant. For example:
div#example {border: 3px solid black; -moz-border-radius: 10px;}

http://halloweentree.net — An Illustration.
The presence of rounded corners introduces an infinite number of tangents to a content block. As some people have mentioned, it focuses attention inwards, because it directs the perpendicular to the tangent inward in a progressive fashion. The break between the point at which the derivative is zero and in which it gains a value (the straight line and the beginning of curvature) is far gentler. Also, these tangents are more exclusive to one content block–it feels less like a grid.
Also, squared edges are natural to things which are being honed from the exterior–things which are cut away. Circles–rounded edges–are natural to things which are grown from within. Why are tree trunks round? Because the radius is the same from every point on the edge–it began from a core and grew outwards. It’s the simplest growth formula. Squares are created by reduction–right angles are the easiest to make work with other shapes because they are caused by the perpendicular cutting of two lines.
Sorry for being long-winded! I agree that trends and difficulty and all that play some part, but I think mathematics show the original article to have revealed something important: that rounded rectangles are fundamentally different in what they communicate than are right-angled rectangles.

I would simply name it eye candy. It’s much more smooth then the straight rectangular layout we saw most time on html-frame or table based sites before.
And with the use of a CMS it becomes easy to the people to use such layouts, since it just means to choose an appropriate template, no div and css tricks to know.
As mentioned above: were are the rounded egdes right here? :O)polarizer

Heck they are both different shapes!!, you choose which suits the bill for your website or graphic design work.
No big deal about which is best, they both fullfil the objective of what you are trying to achieve.
Inward focus, unwanted focal point, aw poop!!, it’s either softer or hard, it’s a penis!!!
It’s a square or curved, not rocket science like most think it is!!!
Shazzam!!!

iLounge (formerly iPodlounge est. 2001) was designed by me and the first iPod 5G introduced in 2001 inspired me to design with rounded corners. It was tabl back then, but it’s all CSS now. I look forward to using the new CSS3 rounded corner spec.

Our attraction to curves is primal, programmed into our genes. As infants, the first shape we recognize–by instinct–is a circle, and for a very simple reason. It is from a circle that we get our food, i.e., mother’s milk. Circle = life.
Now, from a design standpoint, one of the reasons rounded corners look so good is because they force us to include more whitespace than one would use with a right-angled quadrangle.

Its true, we all love rounded corners. Nuvvo now adopts this staple of cool web design not just on nuvvo.com, but throughout your eLearning Portal as well.
The Nuvvo UI has been revamped with lots of graphical improvements to the built-in themes. (Fr…

I still remember (and never much liked) the rounded furniture that was so “modern” in the 50s. I grew up in a house filled with old Victorian curlicues – a different sort of round.
Who here remembers when cars developed rounded edges (in the 90s)? They got rounder and rounder for a few years. Now I think they’re going back again. (they were pretty round in the 30’s and 40s too, then squared out in the 50s.
Things move a bit faster in the online world, so I’d say we’re overdue for edges and corners.
So, I agree with those who said roundedness was a fad. It still seems fresher than a page filled with the old table model, but someone smarter than us here will come up with a way to make straighness look ‘sharp.’

Roundness might be attractive to us because like you said round feels organic, but there are many things in nature which are not round but are organic.
I think that it is a learned behavior that favors the less dangerous smooth round shapes as opposed to the sharp pointy ones. You quickly learn as a child that pointy edges and sharp angles have a greater potential to hurt you. You might think “Hey rocks are round and they still hurt you!” And you would be right, but when all other properties are equal pointy rocks still have greater potential to injure than smooth ones.

I agree, there is something about rounded corners that look much more organic and natural than squares, and I’m glad to see that CSS3 will make creating rounded corners that much easier. However, when it comes to design, I think that sometimes nice squares or rectangles, anything with a hard, pointed corner, really do look better than rounded corners. Table outlines, for example, tend to look a bit odd to me if they’re rounded, just like “buy me now” buttons look too boxy and odd if they’re perfectly square. I think a nice combination of rounded and straight corners are the way to go. For example, in your sample picture, for example, there are so many elements with rounded corners that it actually looks a bit unnatural and weird to me. I would have made the yellow and red boxes perfectly square to help separate them from each other, but that’s just me.

Well, i agree on the organic explanation for using and liking round objects, they are somehow friendly with our way to relate and use things. But with the example of the iPod, there’s a far more simpler explanation for its roundness and whiteness:
The guy that designed the iPod, before he started working with apple, used to design bathtubs and toilets (among other projects), so the explanation is that his great and sexy design of the iPod (that many people loves) is an application of his experience designing bathtubs in a different object.

I still remember (and nowaymore liberal liked) the accented furniture that was so “upstart” in the 50s. I grew up in a blockade filled with old Victorian curlicues – a different sort of round.
Who here remembers when cars proficient light edges (in the 90s)? They got swagsman and losel for a few years. Now I expect they’re debt of nature bet again. (they were bonny round in the 30’s and 40s too, then squared out in the 50s.
Things call forth a bit faster in the online everyman, so I’d say we’re delayed-action for edges and corners.
So, I contract with those who said billowingness was a fad. It still seems fresher than a phrase filled with the old to the purpose art form, but someone smarter than us here will come up with a way to make straighness look ‘clever.’

Well, i agree on the breathing expose for using and sunshine trudging differs, me are in friendly with our way to answer to and use things. But with the example of the iPod, there’s a far for lagniappe simpler body of theory for its globosity and whiteness:
The guy that ambitioned the iPod, before he started fermentation with apple, old to coup bathtubs and toilets (among additional projects), so the emendation is that his duly constituted and gross concert of the iPod (that all-sufficing people loves) is an desire of his experience compositioning bathtubs in a different affair.

“people like the rounded corners because it takes more work to make them”
Interestingly, most early plastic devices (like bakelite phones) were rounded, because that way it is easier to get them out of the mold without damage.